羟丙基化对高直链玉米淀粉理化性质的影响

Effect of Hydroxypropylation on Physicochemical Properties of High-amylose Corn Starch

利用高直链玉米淀粉制备羟丙基化高直链玉米淀粉,醚化剂为环氧丙烷,采用硫酸钠作为淀粉膨胀抑制剂,分别采用XRD测量羟丙基高直链玉米淀粉的结晶情况、DSC测量羟丙基高直链玉米淀粉的糊化温度和焓值变化、Brabender黏度仪测量羟丙基高直链玉米淀粉糊的情况。实验表明:环氧丙烷添加量与取代度呈正相关关系。X-射线衍射分析发现,羟丙基化淀粉的结晶类型没有改变,但是结晶度随着取代度的增加而下降。DSC结果表明,羟丙基化高直链玉米淀粉的糊化特性参数和焓值均降低。Brabender黏度分析表明,羟丙基化高直链玉米淀粉的峰值黏度随环氧丙烷添加量的增加而逐渐升高。凝沉特性分析表明,羟丙基改性能有效地提高其抗凝沉性。

Hydroxypropyl high amylose corn starch was prepared by using high amylose corn starch as raw material, epoxy propane as etherifying agent and sodium sulfate as expansion inhibitor. By means of XRD, DSC and Brabender viscometer, the effect of different epoxypropane dosage on the physicochemical properties of hydroxypropyl starch was studied. The results showed that the amount of epoxy propane added had significant influence on the degree of hydroxypropylylation. With the increase of the amount of epoxy propane added, the degree of substitution basically increased linearly. Brabender viscosity analysis showed that the peak viscosity of hydroxypropylated high-chain corn starch gradually increased with the increase of propylene oxide content. The analysis of coagulation property showed that the hydroxypropyl modification effectively improved the anticoagulability. X-ray diffraction analysis showed that the crystalline type of hydroxypropyl starch did not change, and the crystallinity of starch molecules decreased with the increase of etherification. The results of DSC test showed that the gelatinization parameters and enthalpy of hydroxypropylated high-chain corn starch were reduced.